Internet Protocols - CCIE Routing and Switching Exam Certification Guide - page 304

IP Address Classes Table 6-20

Address Class Address Class Purpose High Order Bits Network Numbers

A For large networks 0xxxxxxx 1.0.0.0 to 126.0.0.0

B For medium networks 10xxxxxx 128.0.0.0 to 191.255.0.0

C For small networks 110xxxxx 192.0.0.0 to 223.255.255.0

D Multicast address 1110xxxx 224.0.0.1 to 239.255.255.255

E Experimental /reserved 1111xxxx 240.0.0.0 to 254.255.255.255

Private Address Space

Table 6-21

Class Type Start Network End Network

Class A 10.0.0.0/8 -

Class B 172.16.0.0/16 172.31.0.0/16

Class C 192.168.0.0/24 192.168.255.0/24

Default Address Masks

Table 6-22

Class Binary Mask Dotted Decimal Mask

A 11111111 00000000 00000000 00000000 255.0.0.0

B 11111111 11111111 00000000 00000000 255.255.0.0

C 11111111 11111111 11111111 00000000 255.255.255.0

Subnet Mask Examples Table 6-23

Dotted Decimal Bit Mask Hexadecimal

255.0.0.0 /8 FF000000

255.192.0.0 /10 FFC00000

255.255.0.0 /16 FFFF0000

255.255.224.0 /19 FFFFE000

255.255.240.0 /20 FFFFF000

255.255.255.0 /24 FFFFFF00

255.255.255.224 /27 FFFFFFE0

255.255.255.240 /28 FFFFFFF0

255.255.255.248 /29 FFFFFFF8

255.255.255.252 /30 FFFFFFFC